March 18 (Reuters) - A Southwest Airlines ( LUV ) flight

forced to abort a landing at Chicago Midway Airport on February

25 to narrowly avoid a collision with a business jet was less

than 200 feet behind it, the National Transportation Safety

Board said on Tuesday.

A FlexJet Challenger business jet entered the runway without

authorization, prompting the Southwest Boeing 737-800 to perform

a go-around, a maneuver in which the plane circled and

reapproached the landing. The Southwest ( LUV ) first officer saw the

business jet and realized it was not stopping, called for a

go-around and the captain executed it, the NTSB said.